Liquid food and beverage preparation apparatuses, in particular coffee machines, which use prepacked or non-packed portions of a food or beverage substance are very widespread among private individuals, and also in municipalities, shopping centres and companies. The preparation principle is based on the extraction of portions of the substance by the passage through this substance of a quantity of cold or hot liquid, typically water, under high pressure, above atmospheric pressure.
Examples of a prepacked portion, or capsule, are described in patent EP 0 512 468 B1 and in patent EP 0 602 203 B1.
Such capsule extraction systems have many advantages. On the one hand, the individual capsules are easy to use and require no batching of coffee or other substances, in the machine. The user places a capsule, a ground-coffee dose or other portions in the machine, then presses a button to start extraction. On the other hand, the individual packages are batched to deliver a beverage, like a coffee, having the desired characteristics such as sufficient character, flavour, foam or other important attributes. When they are impermeable, they usually preserve the freshness of the substance better, up to the time of extraction. Finally, the preparation conditions, such as the temperature, pressure and extraction time can be better controlled, thereby guaranteeing relatively controlled and constant quality to the consumer.
An example of an extraction method is described in patent EP 0 512 470 B1.
Once the capsule has been used to prepare a liquid food or beverage, a used ingredient such as coffee grounds may remain in the capsule. The combination of the capsule and used food or beverage ingredient contained therein causes problems for the recycling. Indeed the recycling of the capsule material and of the used food or beverage ingredient requires different processes, one for the capsule material and a separate one for the used beverage or food ingredient, typically the plastic or metal packaging on the one hand and the organic ingredient on the other hand. Most communities require separation for collection and recycling of the recyclable waste material, such as for instance glass, plastic, aluminium, organic material, etc. . . .
It is known to separate aluminium from a composite aluminium-polymer material by heating the composite material in a non oxidised environment to volatilize the polymer, as for instance disclosed in US 2007/0113705.
Industrial separation of aluminium capsules from coffee grounds involves a first step of drying the coffee grounds and a second step of sucking the dried coffee grounds out of the capsules. Such separation processes require a complex installation and significant amount of energy.
Plastic capsules, on the other hand, are usually not even recycled but merely incinerated or dumped into landfills which causes pollution.
Some places, e.g. Switzerland, have set up an organised community collection system for such used aluminium capsules, in addition to the usual recycling collection, so that the recycling rate of such capsules is quite high. However, many places do not have a separate dedicated community recycling channel for the capsules that combine plastic or metal with organic food or beverage ingredients, so that such used capsules have to be sent back to the producer for recycling by the consumer or they are simply incinerated or dumped into landfills with the non-recyclable household garbage.
Therefore, especially for those places which have not set up a dedicated community collection and recycling system, there is still a need to provide a simple system for allowing collection and recycling of such used capsules containing used or residual food or beverage ingredients.